how to handle two OGL windows

I have created a main OgL window. On this OGL windowi have a window for selection of few objects. In selection window i have a small OGL window for objects preview. When i Create OGL window on my selction window my mailn OGL window does not show me any thing. But if i donot create a samall OGL window on my selection window my main OGL window works fine. How can i solve my problem.

Make sure you synchronise your wglMakeCurrent() calls between the 2 windows.
Only one rendering context can be current at any one time.